#Html.DropDownListFor and #HtmlPagedListPager - asp.net-mvc

Question

I've created an MVC website using VS2013. My view contains a a dropdownlist for "Import Status" and a paging control as shown below:
My view is as follows:
#model PagedList.IPagedList<ESBAMPortal.Models.SupplierStockUpdateViewModel>
#using PagedList.Mvc;
<link href="~/Content/PagedList.css" rel="stylesheet"
type="text/css" />
#{
ViewBag.Title = "Index";
Layout = "~/Views/Shared/_Layout.cshtml";
SelectList itemsPerPageList = ESBAMPortal.Helpers.DefaultValues.ItemsPerPageList;
}
<h2>Stock Updates</h2>
<div class="container-fluid">
<div class="row">
<div id="instruction" class="col-md-6 pull-left">
<h5>Click the 'Process Start' datetime to see a copy of the file received</h5>
</div>
</div>
<div class="row" id="filters">
<div id="filtersDropdown" class="col-md-6 pull-right">
#using (Html.BeginForm("Index", "SupplierStockUpdate", FormMethod.Get, new { #class = "pull-right" }))
{
{
<span>
#Html.Label("Import Status:")
#Html.DropDownListFor(m => m.FirstOrDefault().SelectedStatusId, Model.FirstOrDefault().StatusItems)
</span>
<span>
#Html.Label("Items per page:")
#Html.DropDownList("ItemsPerPage", itemsPerPageList,
new { #id = "ItemsPerPageList" })
</span>
}
<input type="submit" value="Refresh" />
}
</div>
</div>
</div>
<table class="table table-striped">
<thead>
<tr>
<th>#Html.DisplayNameFor(model => model.FirstOrDefault().ReceivedFilename)</th>
<th>#Html.ActionLink("Proces Start", "Index", new { sortOrder = ViewBag.TimeReceivedSort, itemsPerPage = itemsPerPageList.SelectedValue })</th>
<th>#Html.DisplayNameFor(model => model.FirstOrDefault().TimeProductLookupResponse)</th>
<th>#Html.DisplayNameFor(model => model.FirstOrDefault().TimeInsertResponse)</th>
<th>#Html.DisplayNameFor(model => model.FirstOrDefault().ImportStatus)</th>
<th>#Html.DisplayNameFor(model => model.FirstOrDefault().ImportErrors)</th>
<th>#Html.ActionLink("Supplier", "Index", new { sortOrder = ViewBag.SupplierSort })</th>
<th>#Html.DisplayNameFor(model => model.FirstOrDefault().RowsInserted)</th>
<th>#Html.DisplayNameFor(model => model.FirstOrDefault().TimeOfExceptionString)</th>
</tr>
</thead>
<tbody>
#foreach (var item in Model)
{
<tr>
<td>#Html.DisplayFor(model => item.ReceivedFilename)</td>
<td>
#Html.ActionLink(item.TimeReceived.ToString(), "Index", "ArchivedMsg",
new { interchangeId = item.InterchangeId }, null)
</td>
<td>#Html.DisplayFor(model => item.TimeProductLookupResponse)</td>
<td>#Html.DisplayFor(model => item.TimeInsertResponse)</td>
<td>#Html.DisplayFor(model => item.ImportStatus)</td>
<td>#Html.DisplayFor(model => item.ImportErrors)</td>
<td>#Html.DisplayFor(model => item.SupplierCode)</td>
<td>#Html.DisplayFor(model => item.RowsInserted)</td>
#{
if (item.TimeOfExceptionString.IsDateTime())
{
<td>#Html.ActionLink(item.TimeOfExceptionString, "IndexForInterchangeId", "Fault", new { interchangeId = item.InterchangeId }, null) </td>
}
else
{
<td>NA</td>
}
}
</tr>
}
</tbody>
</table>
<div id="pageControllFooter" class="container-fluid">
<div class="row">
<div id="pageButtons" class="col-md-2">
#Html.PagedListPager(Model, page => Url.Action("Index", new { page, itemsPerPage = ViewBag.CurrentItemsPerPage }))
</div>
</div>
<div class="row">
<div id="pageDesc" class="col-md-2">
#if (Model != null
&& Model.PageCount > 0)
{
<div>
Page #(Model.PageCount < Model.PageNumber
? 0 : Model.PageNumber)
of #Model.PageCount
</div>
}
</div>
</div>
</div>
Model:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Web;
using System.Web.Mvc;
namespace ESBAMPortal.Models
{
public class SupplierStockUpdateViewModel
{
public string ActivityID { get; set; }
public string InterchangeId { get; set; }
[DisplayName("Received")]
public DateTime? TimeReceived { get; set; }
[DisplayName("DW Product Requested")]
public DateTime? TimeProductLookupRequested { get; set; }
[DisplayName("DW Product Response")]
public DateTime? TimeProductLookupResponse { get; set; }
[DisplayName("CIMS Insert Requested")]
public DateTime? TimeInsertRequested { get; set; }
[DisplayName("CIMS Insert Response")]
public DateTime? TimeInsertResponse { get; set; }
[DisplayName("Supplier Code")]
public string SupplierCode { get; set; }
[DisplayName("CIMS Records Updated")]
public int? RowsInserted { get; set; }
public string ReceivedFilename { get; set; }
public DateTime? TimeOfException { get; set; }
public string TimeOfExceptionString { get; set; }
public double TotalDuration { get; set; }
public string ImportStatus { get; set; }
public int? ImportErrors { get; set; }
public DateTime LastModified { get; set; }
//constructor
public SupplierStockUpdateViewModel()
{
_statuses = new List<Status>();
_statuses.Add(new Status()
{
Id = 1,
Name = "All"
});
_statuses.Add(new Status()
{
Id = 2,
Name = "Pending"
});
_statuses.Add(new Status()
{
Id = 3,
Name = "Complete"
});
}
private readonly List<Status> _statuses;
public class Status
{
public int Id { get; set; }
public string Name { get; set; }
}
[Display(Name = "Status")]
public int SelectedStatusId { get; set; }
//our VM has a select list
public IEnumerable<SelectListItem> StatusItems
{
get { return new SelectList(_statuses, "Id", "Name"); }
}
}
}
Controller:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using ESBAMPortal.DataLayer;
using ESBAMPortal.Models;
using PagedList;
using ESBAMPortal.DomainClasses.BAM;
using System.IO;
namespace ESBAMPortal.Controllers
{
public class SupplierStockUpdateController : Controller
{
private IRepository<SupplierStockUpdate> SupplierStockUpdateRepository;
public SupplierStockUpdateController(BAMContext context)
{
this.SupplierStockUpdateRepository = new EFRepository<SupplierStockUpdate>(context);
}
private string TranslateStatusFilter(int status)
{
string ret = "";
switch (status)
{
case 2:
ret = "Pending";
break;
case 3:
ret = "Complete";
break;
}
return ret;
}
// GET: /SupplierStock/
public ActionResult Index(string sortOrder, int? page, int? itemsPerPage, SupplierStockUpdateViewModel vm)
{
string statusFilter = TranslateStatusFilter(vm.SelectedStatusId);
ViewBag.CurrentItemsPerPage = itemsPerPage;
ViewBag.TimeReceivedSort = String.IsNullOrEmpty(sortOrder) ? "timeReceived" : "";
ViewBag.SupplierSort = sortOrder == "supplier" ? "supplier_desc" : "supplier";
var query = this.SupplierStockUpdateRepository.GetAll();
switch (sortOrder)
{
case "timeReceived":
query = query.OrderBy(f => f.TimeReceived);
break;
case "supplier":
query = query.OrderBy(f => f.SupplierCode);
break;
case "supplier_desc":
query = query.OrderByDescending(f => f.SupplierCode);
break;
default:
query = query.OrderByDescending(f => f.TimeReceived);
break;
}
if (statusFilter == "Pending" || statusFilter == "Complete")
{
query = query.Where(x => x.ImportStatus == statusFilter);
}
//shove results into view model
List<SupplierStockUpdateViewModel> SupplierStockUpdatesVM = new List<SupplierStockUpdateViewModel>();
DateTime start = new DateTime();
DateTime end = new DateTime();
foreach (var item in query.ToList())
{
SupplierStockUpdateViewModel SupplierStockUpdateVM = new SupplierStockUpdateViewModel();
SupplierStockUpdateVM.ActivityID = item.ActivityID;
SupplierStockUpdateVM.InterchangeId = item.InterchangeId;
SupplierStockUpdateVM.TimeReceived = item.TimeReceived;
SupplierStockUpdateVM.TimeProductLookupRequested = item.TimeProductLookupRequested;
SupplierStockUpdateVM.TimeProductLookupResponse = item.TimeProductLookupResponse;
SupplierStockUpdateVM.TimeInsertRequested = item.TimeInsertRequested;
SupplierStockUpdateVM.TimeInsertResponse = item.TimeInsertResponse;
SupplierStockUpdateVM.SupplierCode = item.SupplierCode;
SupplierStockUpdateVM.RowsInserted = item.RowsInserted;
SupplierStockUpdateVM.TimeOfException = item.TimeOfException;
SupplierStockUpdateVM.ReceivedFilename = item.ReceivedFilename;
SupplierStockUpdateVM.ImportStatus = item.ImportStatus;
SupplierStockUpdateVM.ImportErrors = item.ImportErrors;
start = (item.TimeReceived == null) ? DateTime.MinValue : (System.DateTime)item.TimeReceived;
if (item.TimeOfException == null)
{
SupplierStockUpdateVM.TimeOfExceptionString = "NA";
if (item.TimeInsertResponse != null)
{
end = (System.DateTime)item.TimeInsertResponse;
}
else
{
//no exception but process still running so give a duration of 0
end = start;
}
}
else
{
SupplierStockUpdateVM.TimeOfExceptionString = item.TimeOfException.ToString();
end = (System.DateTime)item.TimeOfException;
}
if (start == DateTime.MinValue)
{
SupplierStockUpdateVM.TotalDuration = 0;
}
else
{
SupplierStockUpdateVM.TotalDuration = (end - start).TotalSeconds;
}
SupplierStockUpdatesVM.Add(SupplierStockUpdateVM);
}
int pageSize = (itemsPerPage ?? 10);
int pageNumber = (page ?? 1);
return View(SupplierStockUpdatesVM.ToPagedList(pageNumber, pageSize));
}
}
}
On clicking the "Refesh" button all works ok, the filtered Import Status is passed to the controller. My problem is, when paging by clicking the boxes of the page controls, the value 0 is always passed in the VM.SelectedStatusId field.
I've tried changing the view's call to explicitly pass the SelectedStatusId as follows:
#Html.PagedListPager(Model, page => Url.Action("Index", new { page, itemsPerPage = ViewBag.CurrentItemsPerPage, Model.FirstOrDefault().SelectedStatusId }))
...and adding a corrsponding int param on the controller action but still this was coming through as 0.
Could anyone let me know where I'm going wrong? Thanks.

Answer 1

Upon first look, it seems you have coded the following line wrong.
#Html.PagedListPager(Model, page => Url.Action("Index", new { page, itemsPerPage = ViewBag.CurrentItemsPerPage, Model.FirstOrDefault().SelectedStatusId }))
You have forgotten the return parameter for the last parameter in you expression. Try the following
#Html.PagedListPager(Model, page => Url.Action("Index", new { page, itemsPerPage = ViewBag.CurrentItemsPerPage, vm = Model.FirstOrDefault().SelectedStatusId }))
note the "vm = "
Let me know if that works!

Answer 2

The vm.SelectedStatusId is passed into the action when the user clicks the "Refresh" button on the view.
I assign the selected status to a viewbag property in the Index action of the controller:
ViewBag.StatusId = vm.SelectedStatusId;
When the user later pages through the results, I pass in the previously selected status filter, from the viewbag:
#Html.PagedListPager(Model, page => Url.Action("Index", new { page, itemsPerPage = ViewBag.CurrentItemsPerPage, selectedStatusId = ViewBag.StatusId }))